To obtain a quick and accurate reading of the body temperature, the probe of a radiation thermometer is simply inserted into the ear canal in order to measure the infrared radiation emitted by the tympanic membrane which is accurately representative of the body's core temperature. In contrast to conventional mercury thermometers, infrared thermometers have proven to operate not only substantially more quickly but also eliminate the risk of cross contamination due to contact with mucous is membranes as may occur, for example, when the temperature is taken orally or rectally using mercury thermometers.
From U.S. Pat. No. 4,602,642 A and U.S. Pat. No. 4,784,149 A radiation thermometers are known having control units with a probe and depository units serving to receive the respective control unit and a supply of protective covers for the probes. Because of their large dimensions, these radiation thermometers are only suitable for stationary use.
From EP 0 565 123 A1 a portable radiation thermometer is known whose probe may be provided with a protective cover for measurement and otherwise may be protected by a housing cap. When a physician, for example, wishes to carry this radiation thermometer with him to visit his patients, it will be necessary for him to carry not only the thermometer but also a separate storage container for the protective covers, because sanitary reasons demand that a new protective cover be used for each temperature measurement. Taking a measurement with such a radiation thermometer is rather a complicated procedure because the housing cap to be removed for measurement needs to be handled as a third individual part aside from the thermometer and the storage container holding the protective covers, making two-hand operation impossible.
From EP 0 502 277 A2 an infrared ear thermometer is known having an enclosed housing to the lower end of which a housing extension is attachable which serves as a storage container for protective covers nested inside each other. This thermometer possesses no housing cap for protection of the delicate probe.
From U.S. Pat. No. 5,088,834 A it is known to arrange a plurality of conical protective covers in a receptacle in nested fashion. A protective cover is installed over a probe by inserting the probe into the topmost protective cover. Suitable protective covers are known, for example, from EP 0 419 100 A and EP 0 472 490 A, which have a window that is transparent to radiation in the infrared region.
From WO 95/00067 protective covers are known having ears ensuring on the one hand a secure seating engagement of the protective cover with the thermometer's probe while on the other hand actuating a switch serving as a detector to establish the presence or absence of a protective cover. A temperature measurement can be performed only with the switch actuated. In lieu of ears, a circumferential reinforcement of the protective cover's rim may also be provided.